What would be a good solid state switch in this situation?

I am building an automotive switch box and have a 12 volt system however the switchbox will contain Integrated Circuits (5v max) so I am reducing the voltage in the switchbox for the ICs. The main reason for ICs and not just plain switches is for programmability and some other functions. For the question at... show more I am building an automotive switch box and have a 12 volt system however the switchbox will contain Integrated Circuits (5v max) so I am reducing the voltage in the switchbox for the ICs.
The main reason for ICs and not just plain switches is for programmability and some other functions. For the question at hand, I will have 5 volts or 0 volts respectively coming out of the IC but the items to be switched work on 12 volts and the modules to be controlled have a tricky setup because they require a positive 12 volts into the module to switch the module on.
(What happens is the module has a positive and negative wire run directly to the battery so the module itself is live all the time however it has an +12v input that internally switches on the purpose of the module. Basically it needs +12v on a 3rd input to turn on)
What I currently do pre-switchbox is have 12 volts off the battery run to a toggle switch which when turned on provides the needed 12 volts.
With the ICs and without relays (need the 3rd input to become live as fast as possible and my understanding is relays do not have as fast a capability as solid state)
Because of the type of IC, I can have it put out 5v on the respective output unless I want 0v or put out 0v until I want the circuit live and then put out 5v. (2nd method preferred as a fail-safe that the IC is not putting out due to malfunction, the circuit is not live.)
So the IC only puts out 5v whereas the input of the module needs 12v. I don't like the idea of a transformer either. I would like to use transitors but cannot find a suitable solution that takes a 5v input and forwards the 12v.

Conclusion-With 5v/0v coming out of the IC, a 12v line coming off the battery, and a line to the 3rd input line on the module, I need the 12v to forward to the 3rd line input based on what is coming out of the IC.
Update: http://www.whelen.com/install/131/13180.pdf is the module that is to be operated. The +12 volts come off the White/Red go through a switch (which I want to be controlled by the IC) then feed back into the Blue and Green inputs according to which strobes I want on. By looking at the pdf, it appears that it will... show more http://www.whelen.com/install/131/13180.pdf is the module that is to be operated. The +12 volts come off the White/Red go through a switch (which I want to be controlled by the IC) then feed back into the Blue and Green inputs according to which strobes I want on. By looking at the pdf, it appears that it will only pull around 100 ma at the max.
Update 2: To clarify, I have +12v coming from a source (battery or module, doesn't really matter) and a output the the module that needs when requested +12v. I need that output's state to directly depend on the state of the output of the IC. There is not a -12v anywhere along this setup.
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